Blade latch for disconnect switches



May` 20, 1958 A. Fo'rl BLADE LATCH Fox lurscorqmac1 SWITCHES 5Sheets-Sheet 1 Filed Sept. 10, 1954 lxwdl- NW m mf r mM 4 n A May 20,1958 A. FoTl i2,835,770

BLADE LATCH FOR DIscoNNEcT SWITCHES Filed sept. 1o, 1954 5 ysheets-sheet2 fr-:KIA

- IESA- u u INVENTOR. b ,eg/yf Far/ May 20, 1958 A. FoTx BLADELATCH EURDIscoNNEcm SWITCHES 5 Sheets-Sheet 3 Filed Sept. 10, 1954 |W #Ell Q.

IN VEN TOR. Mes/v r/ @Jaw g//Zfk May Z0, 1958 A. FOTI l BLADE LATCH FORDIscoNNECT SWITCHES 5 Sheets-Sheet 4 Filed Sept. 10, 1954 May 20, 1958A, F0-rl 2,835,770

ADE LATCH FOR DISCONNECT SWITCHES Filed Sept. 10, 1954 5Sl'leets---Sheetl 5 IN VEN TOR. 74E/W Fr/ 2,835,770 Patented May 20,1958 BLADE LATCH Fon DISCoNNnor SWITCHES Arem Foti, Greensburg, Pa.,assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., acorporation of Pennsylvania Application September 10, 1954, Serial No.455,227

6 Claims. (Cl. 20G-169) My invention relates to a latch arrangement fordisconnecting switches having high pressure contact engagement caused byrotation of the blade about its hinge and axis and is more particularlydirected to latching means for the type of disconnecting switchdisclosed in Patent No. 2,673,902 issued March 30, i954.

In high voltage outdoor disconnecting switches, it is necessary to lockor latch the switch biade in engaged position with the stationarycontacts in order to prevent the blade from being moved out of theposition for proper contact engagement by accidental forces, vibration,or electromagnetic forces created by the passage of short circuitcurrent through the switch.

Heretoore, latch means provided for hook stick operated switches reliedon the mechanical rigidity or" the latching means to maintain the switchblade in closed position. That is, the i'orce tending to move the switchblade from the closed to the open position was exerted directly on thelatching member and this was called upon to withstand the full impact ofthe opening force.

In my novel latch arrangement, i utilize the inherent structuralarrangement or" the disconnecting switch so that the latch provides ameans whereby any opening force applied to the switch blade is resolvedinto a torsional force on the switch blade to thereafter be transmittedback to the closing means.

Thus, the torsional strength of the blade and the strength and rigidityof the stop means of the closing mechanism is utilized to maintain theswitch in closed position. ln effect, the disconnecting switch ismaintained in a closed position by the strength or' the stop meansassociated with the closing mechanism in addition to the latchassociated with the blade.

in the disconnect switch of Patent No. 2,673,902, issued March 30, 1954,assigned to the assignee of the instant application, a closing mechanismis disclosed which has the inherent features to defeat unintentionalopening ofthe switch blade.

The operating mechanism of this switch contains a toggle which isoperated from a crank through one of the supporting insulators. When theswitch is in the open position, the toggle may be moved towards itscenter position by rotating the crank through the insulator to causeclosing operation.

The toggle has a fixed pivot at one end and a movable pivot at its otherend. The movable pivot is connected to a cranli arm which is integralwith a switch blade. Thus, when the toggle is moved from an olt-centerposition toward center position, it will have the dual eirect on theswitch blade to rotate same about its hinge towards the closed positionand also rotate the blade about its own axis.

in the closed position of the switch, the toggle is in the centerposition or slightly beyond the center position and applies a latchiugforce near the hinge pivot of the switch blade.

The disconnecting switch is mechanically constructed so that the closedposition stop means at the base of rotating insulator, the toggle, theclosing crank and the rotating insulator are capable of withstandingopening forces applied to the blade even though these forces may be ofsuicient magnitude to permanently deform the blade.

With my novel arrangement, I utilize the inherent features of theoperating means by relying on the rigidity of these components on oneend of the blade, and employ a latch on the other end to withstand theopening force and eliminate the possibility of the switch bladedeforming as a result of cantilever force exerted thereon such as mayoccur during the existence of severe short circuit currents.

By providing a latch to engage only one side of a flattened portion ofthe switch blade, I resolve any external opening force into a torsionalforce on the switch blade and eliminate cantilever force which isexerted on the blade with the arrangement shown in Patent No. 2,673,902,issued March 30, 1954.

Since the switch blade has great torsional rigidity, the disconnectingswitch will be maintained in closed position without deformation ordistortion of any of the componente thereof when subjected to forceswhich tend to force the switch to the disengaged position.

The above advantages are achieved by placing the latch on one side ofthe switch blade so that an upward force on the blade will force theblade to rotate about its axis. The latch is so positioned that it willresolve the opening forces into a torsional force tending to rotate theswitch blade about its axis in the same direction as its closing motion.Thus, the torsional force on the switch blade will be transmittedthrough the crank on the blade to the toggle means to thereby bring theclosing crank` solidly against the closed position stop means at theswitch base.

Accordingly, a primary object of my invention is the provision of meanswhereby a disconnecting switch can be maintained in the closed orengaged position without exerting cantilever force on the switch bladeeven though magnetic opening forces are exerted on the switch.

Another object of my invention is to provide an attachment means for adisconnecting switch which will resolve forces tending to jar or forcethe switch to the open r position into a torsional force on the switchblade which can be transmitted through the operating means so that therigidity of the operating means will maintain thc switch in the closedposition.

Another object of my invention is to provide a latch for the blade of adisconnecting switch which will tend to rotate the blade about its axisin the same direction as the closing motion.

Still another object ot' my invention is to provide c `er a rigid orresilient latch means for disconnecting swi es `o1? the type shown inPatent No. 2,673,902 issued Marc 30, 1954, which will resolve forcestending to jar or force the switch to t-he open position so that therigidity ot the operating means will maintain the switch in closedposition without reliance on the mechanical rigidity of `the switch'blade as a cantilever beam to resist the forces.

These and other objects of my invention will be apparent from thefollowing description when taken in connection with the drawings inwhich:

Figure 1 is a side view ofthe disconnecting switch with my novel latchmeans adapted thereto.

Figure la is an enlarged opposite side View of the jaw end of thedisconnecting switch of Figure l. nfhis ligure illustrates therelationship of the jaw latch to the blade latch of my invention.

Figure 2 is a view taken in ythe direction of the arrows 2-2 of Figure land illustrates the relationship of the jaw latch to the blade latch ofmy invention,

asssyrvo Figure 2a is an exploded view illustrating the jaw and bladelatch of my invention.

Figure 3 is a view taken in the direction of the arrows 3--3 of Figure land yshows `the base support and lower operating member of thedisconnecting switch of Figure l.

Figure 4 is a cross-sectional view taken in the direction of the arrows4 4 of Figure 1.

Figure 5 is a top view of the disconnecting switch of Figure l showingthe position of the toggle mechanism when the switch is in the closedposition. This ligure also illustrates a top view of the novel blade andjaw latch of my invention.

Figure 6 is a top view of the switch of Figure l and illustrates theposition of the toggle mechanism waan the switch is in the disengaged oropen position.

Figure 7 is a top view of the switch of Figure l and shows the positionof the operating toggle after the movable contacts have entered thestationary contacts and have just started to rotate into high -contactpressure.

Figure 8a is a side view of the jaw latch used in my invention.

Figure 8b is a View taken in the direction of the arrows b-Sbillustrating the side view of the jaw latch.

are 8f.: is a View taken in the direction of the tic-8c ot Figure 8billustrating the vtop view of the jaw latch.

Figure 9a illustrates a front view of the blade latch.

Figure 9b is a View taken in the direction of the arrow-s ,Gib- 9b ofFigure 9a illustrating the side view of the blade latch.

Figure 9c is a view taken in the direction of the arrows 9c9c of Figure9b and illustrates a top View olf the blade latch.

Figure l0 is a fragmentary enlarged top view of the crank and linkmechanism for operating the contact arm vand corresponds to Figure 6`This figure illustrates the position of the 4toggle when the Iswitch isin the fully open position.

Figure 1l is a top view similar to Figure l() but illustrating theposition of the toggle after the conta-ct arm has entered the stationarycontact jaws but has not yet lbeen rotated to the closed position andcorresponds to the position illustrated in Figure 7.

Figure l2 is a top View similar to Figures l() and ll and illustratesthe position of `the toggle when the switch is in the fully closedposition. This gure illustrates the toggle moved over its center lineposition during the final stroke of the closing operation.

Referring first to Figure 1, the disconnecting switch l@ is mounted onthe base 1l which is a suitable longitudinal structural support, in thiscase shown horizontally arranged for a horizontally or upright mounteddisconnecting switch.

The base ll has secured thereto in any suitable manner as by theinsulator spacers 1.2 and 13 the stationary upright supporting posts 14,15 on the upper portions of which are mounted insulators i6, 17.

Base li is also provided with the bearing 2@ appropriately securedthereto in any s-uitable manner as by the bolts 2i and carrying therotatable vertical shaft 22, to the upper end of which is keyed theinsulator 23 for rotation with the vertical shaft or post 22.

Below insulator 23 there is keyed to the shaft 22 the crank Si) securedthereto in any suitable manner as by the bolts 3l connected to theflange or crank plate 315. Bolts 2 which secure the bearing 2t) inposition also secure the stop plate 3ft in position, the stop platebeing provi-ded it opposite ends with `the adjustable stops 36, 37 whichengage at either end with the stop 3S on the operating crank 3?.

While stops 36, 37 are herein provided, the construction and operationof my novel switch is such that it may operate properly without thestops at individual poles; in

such case, the stops would be provided at the operating means for theentire switch.

Shaft 22a extends above ythe insulator 23 as an effectively continuationof vertical shaft 22, being, however, spaced therefrom by insulator 23.Crank ttl at the upper end of shaft 22a is preferably integral therewithand. therefore, rotates therewith.

Crank itt extends horizontally or at least parallel with the basesupporting structure 1l and rotates in the horizontal plane. Crank 4d isshown herein as tubular although it may have any desired cross-sectionconsistent with the mechanical loads imposed thereon. The outer end ofcrank itl is flattened at il and is provided with a circular opening 42through which pin 43 may pass.

A clevis member ii receives extension 4l and is provided at its oppositelegs 45, i6 with openings register-ing with opening d2 in extension 4lof the crank di) and receiving the pin d3.

:Clevis fill is integral with the threaded extension which enters intothe tapped opening 5l in the forked link 52. The threaded extension Silis so arrange-d that when the threaded extension 59 rotates `withrespect to the forked link 52 and its tapped opening 5l, it has linearmovement with respect thereto.

Pin .69a passes through openings 58, 59 and 6G hinging the forked 'link52 to the crank 6l. Where desirable, insulating bushings 6% (see Figure4) may serve as `bearings and to effectively electrically insulate crank61 from pin oder and its forked link 52. rihe blade support sleevecasting 62 carries the tubular switch blade 63 `secured therein androtatable therewith.

The outer end of the tubular switch blade is liattened at 64 (Figure l)is provided with appropriate contacts 65 engageable with the stationarycontact jaws 66.

The blade support sleeve casting 6L?. is mounted for rotation around itslongitudinal axis on an extension of the hinge casting 7d. The hingecasting 7? is, in turn, rotatably mounted by the hinge bearingsindicated generally at 72 on the fori/:ed trame casting 733.

The frame casting 73 cured in any suitable manner as by the bolts r75 tothe top of insulator lo. The si ies 76 of the frame provide supports forthe hinge bearings 72 forming the members 76e', 7652. Sides to extendback to the solid portion 77 which is provided with an opening 78(Figures 5, 6 and 7) appropriately recessed tc form a bearing for crank40' and its shaft 22a.

The solid portion 77 ot the trarne casting 73 then ex tends beyond toform the terminal titl to which appropriate leads may be connected.

The jaws comprises the plurality of contacts and on each side biasedtoward each other by the spring fingers 92, and so a ranged that whenthe blade 63 enters at an angle to the horizontal position during theclosing operation, it will clear the contacts 9d and 91 on each side.

rthese Contact members lare so arranged, however, that when the blade isrotated from the position of Figure 7 to the position of Figures l, 2and 5 tl blade 55 in turning to the horizontal position will spread thecontacts 9i? and 9i on each side against the force of springs 92 and 93creating the Yesired contact pressure.

The spring fingers 92, 93 are current conducting and are connected inany suitable manner as by the bolts 98 to the base plate il@ which, inturn, is mounted in any suitable manner as by bolts iilti at the top ofthe insulator i7.

The base of stationary contact structure 66 has an extension lili. whichserves as a terminal block or connecting member. Thus, when thedisconnecting switch is in the closed position of Figures l and 5, thecurrent enters through terminal titi, passes through the frame casting73 to the hinge bearings 72, then through the current carryingconnection in the hinge bearing 72 to the hinge casting 70, then throughthe current carrying has horizontal section 74 seasesgtvn U connectionfrom the hinge casting 70 to the contact blade 63, then through thecontact 65 on the contact blade 62tto the stationary contact elements90, 91 and then through the base 99 to the terminal extension 101.

The mechanical operating elements which operate the contact assembly forannular rotation at the bearings 72 and after the contact eiernent 56has entered the stationary Contact continue on to rotate the blade 63into appropriate 'contact pressure are shown in side view in Figure i,but their operation is illustrated more clearly in Figures 5, o and 7which show, respectively, the full closed position, the full openposition, and the partly closed position where the blade has beenrotated for entry into the stationary contact without having beenrotated on its longitudinal axis to the closed position of Figure 5,

The relationship ofthe crank to the link at each of the operatingpositions is also demonstrated in Figures l0, ll and l2 which show theseelements and correspond, respectively, to Figures 6, 7 and 5.

The corresponding operation of the lower operating crank is illustratedschematically in Figure 3.

The basic problem here is to utilize the single operating crank in sucha manner that by a continuous motion it will iirst rotate the contactassembly angularly about the hearing i2 and after the end of the blade63 has registered with the stationary contact jaws 66, it will rotatethe blade so that its contact element 65 will be in appropriate highpressure engagement with the stationary contact and will be locked intoclosed position engagement by the past center crank position so that anymagnetic or mechanical or weather forces will tend to drive the parts inthe closing or engaging direction. Movement past center provides forpossible contact en gageinent over a substantial arc so that the contactwill engage despite minor misalignments caused by wear or other factors.

The successive steps from the open to the closed position require,therefore, that the crank 4Q, link 52, and the sleeve crank 6i beconnected in such manner that these various operations may occur.

in this full closed position, the sleeve crank 6i extends substantiallyvertically in the case of an upright mounted switch and, therefore, in aplane which includes the axis of supporting posts 15, i4 and 22.

As the crank 40 on post 22 is rotated with the lower operating crank Silfrom the position of Figure 5 toward the position of Figure 7, the endof link 52 adjacent crank 40 rotates laterally with the crank 4t). Thisresults in pulling the sleeve crank 61 laterally or angularly, therebyrotating the sleeve casting 62 around the extension Zitti. This in turnrotates the blade 63 with the sleeve 62 in order to effect a rotation ofcontact 65 out of horizontal position and, therefore, out of pressureengagement with the stationary contact jaws 66.

This is the condition which is reached at Figure 7. Thereafter, furtherrotation of crank 4t! from the position of Figure 7 and ll to theposition of Figure 6 and l0 results in moving the link 52 toward theleft (with respect to Figures 6 and 7) thereby pulling crank 61 towardthe left and lifting the entire contact assembly angularly around thehinge bearings 72 which act as the rotatable bearing therefor.

The connection between link 52 and sleeve crank 61 has already beendescribed. This connection formed by pin 66a through openings 58 and 39of link 552 and open-- ing 6b of sleeve crank 61 permits rotation of thelink 52 with respect to the sleeve crank 6l in that plane only whichincludes both the axis of the link 52 and the axis of blade 63.

However, the connection between the crank 413 and link 52 must be suchas to permit rotation in two planes. ln addition, since the link 52first rotates with sleeve crank 61 and sleeve 62 about the stationarybearing 210i) while crank 46* is `rotated in a horizontal plane to movethe switch to its upright position, there must not only be a connectionbetween the crank 4u and link 52 which permits relative rotation in twoplanes but also the connection must permit of some adjustment in thelength of link 52 in order to compensate for the fact that crank 4t)always rotates horizontally about a vertical axis, while the crank 61 towhich the other end of link 52 is connected rotates during the initialportion of the closing operation vertically about a horizontal axis andat the end of the closing operation rotates about another horizontalaxis normal to its first axis of rotation.

Link 52 must also, therefore, have an automatically adjustable compositemotion to maintain appropriate driving connection between crank 40 andcrank 61. Preferably, as shown, the adjustment is made by means of lefthand threaded screw 50 at the connection between elements 40 and 52.This cooperates, as hereinafter pointed out, with the right hand threadof nut 255 to have an additive effect to compensate for the necessarydifferences in link length required as the elements 40 and 52 move froman angular position -through a straight line position to an angularposition on the other side of the straight line positions.

As the crank 40 rotates initially from the closed position of Figure 5toward the released position of Figure 7, its initial angular movementcaused only a relatively very small translatory movement in alongitudinal direction of rink s2.

After the crank 40 has reached and even passes the position of Figure 7on its way to the full open position of Figure 6, the increasing anglewhich the crank makes with the link produces relatively greatertranslatory movement of `the link 52.

At this time, therefore, the link 52 is drawn rapidly to the left toopen the switch rapidly; but at the initial opening movement thetranslatory motion imparted to the link S2 is relatively very small (themajor motion imparted being the rotation about a longitudinal axis oflink 52), and the amount of compensation required in the connectionbetween crank 40 and link 52 to permit an effective lengthening of thelink 52 is also relatively small.

Compensation is provided by a clevis member 44 having the tines 45, 46in which are placed aligned openings 47, 48. The elevis member 44 tsover extension 41 of the crank 4t) with the openings 47, 48 thereofaligned with the opening 42 in extension 41. An appropriate pin 43 ispassed through all of the openings 47, 48, 41 and is locked in positionin any suitable manner.

The clevis member 44 now is secured to the crank 40 so that it mayrotate in a horizontal plane with respect thereto, while it may have atranslatory movement in the horizontal plane. The elevis member 44 ispreferably shaped to allow a rocking motion to prevent binding at thepin 43.

The opposite end of the elevis member constitutes a left-hand threadscrew 50 entering into threaded engagement with the similarly threadedtapped opening 51 at the left-hand end of link 52.

The screw threads 51 and 50 are so arranged that when the crank 40 ismoved from the position of Figures 5 and l2 to the position of Figures 7and l1, resulting in rotation around a longitudinal axis of the link 52and crank 61, the resultant relative rotation between the link 52 andthe elevis member 44 will cause a screwing out of the end 50 of theelevis member 44 from the tapped opening 51 of the link. The pitch ofthe threads 50 and 51 are, therefore, such that this screwing out ofmember 50 from the tapped opening 51 will substantially equal the amountby which the link S2 must be extended during this rotational operationin order to remain engaged with the crank 61. This operation is achievedby a left hand thread on screw 50.

The pitch of the thread of screw 50 may be adjusted to provide theequalizing factor above noted. This may,

however, require a special non-standard pitch to obtain the in and outcamming effect required. The screw Sil is essentially a cam for thispurpose. However, the righthand thread of nut 255 permits the bladeassembly 63- 62-61 to move out from casting 70 when screw Sil moves outof the opening 51 and vice versa, thereby having an additive effect withscrew 50 by moving the pivot 57 of link 52. This additive effect permitsthe required adjustment to take place without the use of special screwpitches. This is possible especially since the height of contact jaws 66permits the contact to be made Without limitatio-n to an exact area ofcontact but at various points within the jaw area.

On release of the contact 65 from the stationary contact 66, the clevismember 44 including its threaded end 50 will now pull on the link 52,drawing it to the left and to the open position of Figures 6 and 10.

Similarly, when the contact member is moved from the position of Figure6 to the position of Figure 7, there will first be a full translatingmovement, the threaded member permitting such rotation of link S2 withrespect to crank 4t) to occur as will permit this translating movementto take place.

Thereafter when the crank moves from the position of Figures 7 and lltothe position of Figures 5 and l2, the threaded member 50 will bescrewed into the tapped opening 51 of link 52 as the relative rotationoccurs between crank tu and link 52 to achieve the fully closedposition, and this entry of member 50 into opening 51 will,in`cooperation with the additive effect of nut 255, be substantiallysufficient to compensate for the necessary reduction in link length, andpermit the crank to move past center as above described.

The stationary contacts 66 have been partially described in connectionwith the operation of the blade 63 and its cooperating contacts 65.

lt will be noted that the jaw end of the disconnecting switch may havethe straight line construction as illustrated in the figures and incopending application Ser. No. 389,099, led October 29, 1953, or may beof the construction shown in Patent No. 2,673,902, issued March 30,1954.

The stationary contact comprises the base 99 which is secured in anysuitable manner as by bolts 1d() to the top of insulator 1'7". It willbe noted that the jaw latch 110 is provided with a base 111 havingopenings 1112 therein. The bolts d which serve to secure the base 99 tothe insulator 17 also serve to secure the jaw latch 11i) to the base 99.The base 99 has a casting extension member to support the conductingportion of the stationary contact comprising the jaws 9h, 9i and theterminal 101.

The spring fingers 92, 93 are secured by the bolts 98 to the terminal101. Each of the spring fingers 92, 93 is sufficient in cross-section tocarry the current from its associated contact member 90, 91. The contactmember 9o, 91 are secured at one end to the spring iingers 92, 9?. Thecontact faces of the contact members 94), 92. are under cut at 95 toprevent upward movement of the movable Contact 65 when it is turned inthe horizontal position. Each of the contact members 90, 91 is providedwith an under cut ledge t) at its outer side to; facilitate thesecurment of the contact members to spring fingers 90, 92, 93.-

The spring 92, 93 bias the contact members 90, 91 toward each other.However, these contact elements are properly adjusted to permit freeentry of the movable contact 65 when it is turned at a substantial angleto the horizontal but are so spaced that they will be spread apart bythe vrotation of the movablel contact members 65 to the lower horizontalposition. Thereafter the spring members 92, 93 force the contacts 90, 91inwardly to exert. appropriate'contact pressure on the side of themovable contact 65.

A blade latch casting 120 is secured by means of the bolt 121, whichpasses through the opening 122, to the end 64 of the blade 63. The bladelatch 120 is provided with an extended portion 123 having a latchingsurface 124. When the switch is in the closed position as indicated inFigures l, la, 2, 2a, the latching surface 124 of the blade latch 120 ispositioned below the latching surface 125 of the jaw latch 110.

As heretofore noted, the blade 6E is rotated about its own axis when itis moved to the closed position. ln the evznt the latch member 11) is arigid unit, the latching surfaces 12d, 125, respectively, of the bladelatch 12) and the jaw latch 11G) may be displaced at an appropriatedistance from the axis of the blade to permit rotation of the bladeduring the closing operation without engaging the latch 11i?.

However, in some applications, it may be desirable to make the latchmember a iiexible or resilient inember to improve operation under iceloading. Thus, with this arrangement, the latch lili) will be sopositioned relative to the lade latch 12th that rotation of the blade 63during the closing operation will bring the extended portion 123 intoengagement with the upper portion 126 of the latch 110.

Thus, a supporting portion 127 of the latch 11i) will be forced todeflect to the right as viewed in Figures 2a and 8o, thereby breakingany ice previously formed thereon.

During the initial opening operation, the blade latch 12o is rotatedfree of the latch surface 125 of the jaw latch 110.

ln the event the switch is in the closed position, as indicated byFigures l, la, 2 2a, 3, 5 and l2, the cooperation of the latch surface124 with the latch surface 125 due to external forces respectively ofthe blade latch 12b and the jaw latch 1.21 will impart a torsional forceon the blade 63 when there is a force which tends to jar or force theblade 63 out of engagement with the jaw il, 91. That is, if the blade 63is accidentally engaged by a moving object or is moved in the opendirection by vibration or a force created due to the occurrence of ashort circuit current, the blade 63 will be moved upwardly so that thelatch surface 124 of the blade latch 129 will engage the latchingsurface 125 of the jaw latch 10.

Since the right side of the blade will be prevented from having furtherupward movement due to the engagement of these two latch surfaces, atorsional force will be exerted on the blade 63 due to the lever arm123.

As heretofore noted, since the link and crank or toggle dil-52 are inthe overcenter position indicated in Figures 5 and l2, the torsionalforce on the blade 63 will tend to drive the members ttl- 52 furtherovercenter. Since this motion will be transmitted through the rotatinginsulator 23 to the operating crank 3ft), this member will be solidlyagainst the stop 36 as indicated in Figure 3. Thus, even though there isa force which tends to open or disengage the disconnect switch 16, therigidity of the stop member 36, column 22 and members Sii- 52 willprevent upward or opening movement of the switch blade 63.

However, since there is engagement between the blade latch and the latch127 on one side of the blade 63, the force tending to litt the blade outof the jaw contact will be resolved into torsion in the blade 63. Hence,the disconnect switch will be maintained in the closed position withoutreliance on the mechanical rigidity of the cantilever beam created bythe blade 63. That is, the blade 63 will only be required to resist thetorsional force caused by the engagement of the latch 116 and E29 andthe mechanical rigidity of the operating means 36, 3i), 22, 4t), 52 willresist the opening force.

Thus, with the novel arrangement of the blade latch 32) and the, jawlatch 110 positioned on the right side of the blade 63, it is possibleto transmit a torsional assetto force to the blade which is in the samedirection as the motion of the blade about its own axis during theclosing operation to thereby enable the operating parts to withstand theforce tending to jar or open the switch without subjecting the switchblade d3 to a cantilever force.

lt will be noted that the invention has been described in connectionwith a switch which has clockwise rotation about its hinge andlongitudinal axis during the closing operation. However', it will beapparent to those skilled in the art that my novel arrangement can beadapted to a switch having a countercloclcwise rotation about its airisduring the closing operation. ln this case, the latch would merely bereversed to the left side so that it will be able to transmit atorsional force to the contact blade which is in the same direction asits motion during the closing operation. That is, the latch members 110and are so placed that forces tending to lift the blade out of contactare resolved into torsional forces which impart motion to the bladewhich is in the same direction as the closing motion.

ln the foregoing, l have described my invention only in connection withpreferred embodiments thereof. Many variations and modifications of theprinciples of my invention within the scope ol` the description hereinare obvious. Accordingly, l prefer to be bound not by the specicdisclosure herein but only by the appending claims.

l claim:

l. ln a disconnecting switch having a hinge end, a jaw end and a movableblade; said movable blade pivotally mounted at said hinge end and havingan engaged and disengaged position with respect to said jaw end; saidblade rotated about its hinge end and about its longitudinal airis whenmoved from said disengaged to said engaged position; latch means securedat the jaw end of said movable blade; said latch means being operativelypositioned and constructed for resolving forces which tend to move saidmovable blade from said engaged position to said disengaged positioninto a torsional force which is in the same direction as the motion ofsaid movable blade about its longitudinal axis when said movable bladeis moved from said disengaged position to said engaged position; saidlatch means being comprised of a jaw latch and a blade latch; said jawlatch being mounted on jaw end of said disconnect switch; said bladelatch being mounted on said movable blade of said disconnect switch;said jaw latch being spaced from said blade latch when said movableblade is in said engaged position.

2. In a disconnecting switch having a jaw end, a hinge end and a movableblade; said movable blade pivotally mounted at said hinge end; saidmovable blade having an engaged and disengaged position with respect tosaid jaw end; a blade latch secured to said switch blade at said jawend; a jaw latch secured to said disconnecting switch at said jaw end;said switch blade having rotation about its axis when moved from saiddisengaged position to said engaged position; said jaw latch spaced fromsaid blade latch when said switch blade is in said engaged position;said blade latch engaging said jaw latch when external forces tend tomove said switch blade from said engaged position to said disengagedposition; engagement of said jaw latch by said blade latch resolvingsaid external forces into a torsional force on said switch blade torotate said switch blade in a direction about its own axis to therebymaintain said disconnecting switch in closed position.

3. In a disconnecting switch having a jaw end, a hinge end and a movableblade; said movable blade pivotally mounted at said hinge end; saidmovable blade having an engaged and disengaged position with respect tosaid jaw end; a blade latch securec said switch blade at said jaw end; ajaw latch secured to said disconnect switch at said jaw end; said switchblade having rotation about its axis when moved from said disengagedposition to said engaged position; said jaw latch spaced from said bladelatch when said switch blade is in said engaged position;

-said blade latch engaging said jaw latch when external forces tend tomove said switch blade from said engaged position to said disengagedposition; engagement of said jaw latch by said blade latch resolvingsaid external forces into a torsional force on said switch blade torotate said switch blade in a tir-st direction about its own axis tothereby maintain said disconnecting switch in closed position.

4. Latch means for a disconnecting switch comprising a blade latch and ajaw latch; said disconnect switch having a blade pivotally mounted atone end for movement to and from yclosed and opened position, said bladelatch being mounted on lsaid blade, said blade latch displaced from saidjaw latch when said disconnect switch blade is in a normally closedposition; said blade latch engaging said jaw -latch when external forcesare created to open said disconnecting switch blade; said blade latchand said jaw latch being operatively positioned and lconstructed wherebyengagement of said jaw latch by said blade latch is operative to resolvesaid external forces to maintain said disconnect switch blade in aclosed position.

5. Latching means for a disconnecting switch comprising a blade latchand a jaw latch; said disconnect switch having an engaged and disengagedposition; a blade having a hinge end and a free end; said bladepivotally mounted at the hinge end thereof; said blade moved fromdisengaged position to said engaged position by rotation of said bladeabout said hinge end and about the longitudinal axis thereof; said bladelatch secured to the free end of said blade; said `blade latch spacedfrom said jaw latch when said blade is in engaged position; said bladelatch engaging said jaw latch when external forces tend to move saidblade from said engaged position to said disengaged position; saidengagement of said jaw latch by said blade latch imparting a torsionalforce on said blade in the same direction as the motion of said bladeabout its axis when moved from said disengaged position to said engagedposition.

6. Latching means for a disconnecting switch comprising a blade latchand a jaw latch; said disconnect switch having an engaged and disengagedposition; a blade having a hinge end and a free end; said bladepivotally mounted at the hinge end thereof; said blade moved fromdisengaged position to said engaged position by rotation of said bladeabout said hinge end and about the longitudinal axis thereof; said bladelatch secured to the free end of said blade; said blade latch spacedfrom said jaw latch when said blade is in engaged position; said bladelatch engaging said jaw latch when external forces tend to move saidblade from said engaged position to said disengaged position; saidengagement of said jaw latch by said blade latch imparting rotation tosaid blade in the direction said blade is rotated when moved to saidengaged position thereby forbidding motion of said blade from saidengaged position to said disengaged position.

Scheuermeyer Nov. 21, 1950 Jamison Aug. 2, 1955

